Method of producing fibrous building compositions



June 14,1949 2,473,19

. l 2 This invention relates to improvements in the bituminous materials used for waterproofing and methods of manufacturing paper, paper felt, and cementing.

' paper boards, and particularly in the manufac- Other objects of this invention will be more ture of paper, paper felt, and paper boards that readily understood after reading the following are impervious to moisture and water, and capable 5 description. of high resistance to damage under handling and According to this invention, bagasse or other other stresses, even when subjected to extreme fibrous material was broken up or pulverized in a temperature changes. hammer mill and mixed with flux oil up to an Fibrous pulp is produced principally by meamount of about part of flux oil to 1 part of METHOD OF PRODUCING FIBROUS v BUILDING COMPOSITIONS Charles M. Baskin, Toronto, Ontario, and Norman W. McLeod, Sarnia, Ontario, Canada, assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application July 1, 1944, Serial No. 543,196. In Canada July 19, 1943 13 Claims. (Cl. 92-21) UNITED STATES PATENT OFFICE chanical grinding whereby the wood or other fibre. This mixture was then charged intoa stapulp-forming material such as bagasse from tionary pressure cooker and digested with a 1.5 wa t sugar e, lt ha t is disintegrated r Be. solution of caustic soda at 100 lbs. pressure for pulverized by rough tones rotating against the 2'hours. The digested mass was beaten and regrain, by hammer mills or other disintegrators duced to a fairly fine pulp, during which process and by chemical digestion. In either case, the 15 e p lverized asphalt and additional flux oil was pulp before it is processed and converted into added to give an overall total of fl il equal t paper, cardboard or building board, is always dia u /12 Pa t fl x Oil t 1 part of fibre. A uni- ]uted t water, Pulp as produced is really a form dispersion of the pulverized asphalt and flux suspension of small quantities of fibre in large oil in the digested mass was then obtained and quantities of water. In the process of producing there Was o o ty With a p dhering to roofing paper, the pulp is first mad i t a paper the screens while removing water by means of or as it is commonly known in the roofing in- I pressure. The sheets 02' pads thereby obtained dustiy, felt. This felt is then transported to the contained about 60 to QLZI ll and were roofing plant and treated by saturating with flux p s ed through a drier at a temperature of about oil, asphalt, or a mixture of flux oil and asphalt, and then repressed While hot herethen coated with a higher melting point asphalt, Sultant Sheet r b a a o t e verage, which coating is imbedded with various types of e at ro f than s andard satu at d asphalt mineral covering material and the sheet is then ofing. The proportions of asphalt to fibre in made up in rolls or cut into shingleg In the prothe fibrous board were 121 by weight whereas the a ti of r fi t paper sheet or f lt, 30 standard asphalt saturated sheet contains at tains as a, rule, very little mechanical wood pulp least of asphalt to 1 of fi e. but is largely disintegrated and pulped rags, and Alternate]! it Was f und hat if the mechanisome chemically digested long-fibre wood pulp. Cally broken p S ar Cane or other fibrous mabje t of thisinventionis t provide ametl'h terial is mixed with the fiux oil and allowed to od whereby bitumen impregnated paper, paper stand for 1 to 2 weeks, very definite and material felt, or paper boards, are turned out directly from improvement is obtainedv not o y n he disa paper making or paper board making machine, persion of the flux oil and powdered asphalt and and the necessity for the present process of satufiller during the eat process but particularly rating with a bituminous material is eliminated. in the Water-proofing o t e final product. It Another object of this invention is to provide 0 was found that the l r the mixture of mea method for turning out waterproof or moisture chanically d s n egrated bagasse and flux 11 i proof paper, paper felt, or paper board directly allowed to remain in the stock pile before cooking from a paper making or paper board making or digesting, the better is the subsequent dischine, in which the bituminous material is conpersion in the beater d e mo e Waterproof tained in the inner portion of the paper sheet, the finished P paper felt, or paper board, but does not show on Lime may be W in the digestion and it is th outside layers This is an improvement over preferred in that it is relatively inexpensive and existing methods, and eliminates the necessity for available in all localities. the present process of laminating two or more Another desirable feature in using lime is that sheets of paper using bituminous cements. the lime soaps or any combination of lime with A further object of this invention is to modify lignous material are invariably insoluble in water, the characteristics of the waterproofed paper, whereas the products of reaction of lignous matpaper felt, or paper board. by incorporating heavy ter with caustic soda or soda sulflte or sulfate are metal salts of organic acids, such as aluminum all exceedingly water-soluble. When lime is used, naphthenate, copper naphthenate, etc.. into the it was found preferable that mechanically dismixed with a clay-water-asphalt slurry,

integrated bagasse and flux oil be premixed and allowed to soak for several days, and preferably for two weeks or longer.

It is not necessary that the asphalt be used in powdered form as it was found that high softening point low temperature susceptibility asphalt, for example having a softening point of about 140 to 240 F., may be used. As these particular high softening point-low susceptibility asphalts can not be pulverized in that they may be rubbery and tacky, they may be dispersed in stone dust or clay-water slurries to obtain an asphalt-clay-water paste wherein the asphalt is dispersed in extremely fine particles, in fact, considerably finer than current asphalt powders. The use of clay was found to be preferable over the use of stone dust as dry clay can be pulverized in a hammer mill and then plasticized with water at a lower cost than reducing lime stone or the like to a fineness below 200 mesh. Clay when properly plasticized makes a much finer filler than stone dust. fillers with high softening point-low temperature susceptibility asphalt, a more pliable final product is obtained.

For example, mechanically disintegrated bagasse is mixed with flux oil and stored for one or two weeks and then digested with a lime solution of about concentration for about 2 hours at about 100 lbs. per square inch steam pressure. This mass of digested disintegrated fibrous material and flux oil is next mixed with a clay-waterasphalt slurry, then dispersed as a pulp, and finally picked up by the continuous blanket of the wet machine. If a waterproof paper is being produced, the paper felt is removed from the blanket and passed through steam heated rolls for drying. If a waterproof board is being produced, the thick paper felt after being removed from the blanket is carried by a conveyor through a long hot air tunnel where it is dried.

Alternatively, asphalt cement, or a combination of asphalt cement with a heavy metal salt of an organic acid, such as aluminum naphthenate, copper naphthenate, etc., is dispersed in a mixture of clay and water to form an asphaltclay-water paste. After this paste is formed, it can be reduced to a slurry of any desired consistency by incorporating additional water.

For example, mechanically disintegrated bagasse is mixed with flux oil and stored for one or two weeks or longer, and then digested with a lime solution of about 10% concentration for about 2 hours at about 100 pounds per square inch steam pressure. This mass of digested disintegrated fibrous material and flux oil is next (in which up to 75% of heavy metal salts of organic acids such as aluminum naphthenate, copper naphthenate, etc., may be incorporated in the bitumen) then dispersed as a pulp, and finally picked up by the continuous blanket of the wet machine. If a waterproof paper or paper felt is being produced, the thin felted layer is removed from the blanket and passed through steam heated rolls, or through a long hot air tunnel, for drying. If a waterproof paper board is being produced, the

By using clay or stone dust thick felted layer, after being removed from the blanket, is carried by a conveyor through a long hot air tunnel where it is dried.

It is sometimes desirable to introduce the waterproof material between layers of paper so that the waterproofing material would be contained in the inner portion of the sheet and would not show on the outside layers. This may be readily done by forming one or more layers of paper felt introducing asphalt-clay-water suspension into one or more succeeding layers of paper felt, and finally covering with one or more layers of the paper felt, all of these operations being carried out as the layers of paper felt are being built up on the continuous blanket of the wet machine. This may be accomplished by either one or both of the following two methods:

1. In a paper machine consisting of several compartments, the clay-water-asphalt paste or slurry can be dispersed with the pulp in one or more of the central compartments, but not in the end compartments. In this way the blanket picks up a layer of paper pulp from the wet cylinder in the first one or more compartments, followed by a layer of paper pulp containing the claywater-asphalt dispersion, from the wet cylinder in each of one or more of the central compartments, and finally picks up a layer of paper pulp alone from the wet cylinder in each of one or more compartments in the end of the machine. By this procedure, a waterproofed paper sheet or paper board is obtained, which consists of central layers of pulp fibre impregnated with asphalt, contained within an envelope of outer layers of pulp fibre which do not contain asphalt.

2. This method is similar to (1) with the exception that in one or more of the central compartments of the wet machine, where the inner layers of the paper sheet or board are formed, the asphalt-clay-water slurry or paste is introduced into the pulp just as the fibre is being picked up by the wet cylinder, by spraying, etc.

In all cases, it should be clearly understood that the bituminous material used in the above processes for waterproofing and cementing purposes, may contain up to about 75% of metal salts of organic acids, such as aluminum naphthenate, copper naphthenate, etc. These compounds may be dissolved in the hard asphalt, in the flux oil, or both. They may also be added separately at some stage in the process, where they will combine with the bitumen, fibre, and mineral filler. These metal salts of organic acids modify the rigidity or pliability and other characteristics of the waterproofed paper sheet, paper felt, or paper board.

We claim:

1. A method of preparing a building composition which comprises breaking up a fibrous material into a state of fine subdivision, adding about part of a flux oil to about 1 part of the divided fibrous material, adding an alkaline solution to the mixture of fibrous material and flux oil, digesting at lbs. per square inch steam pressure for two hours the fibrous material, flux oil and alkaline solution to form a fibrous pulp, dispersing in the fibrous pulp an asphalt and flux oil, picking up the mixture of fibrous material, flux oil and asphalt in layers on a continuous blanket to form sheets, and submitting the said sheets of fibrous material, asphalt and flux oil to pressure and heat to remove water.

2. A method of preparing a building composition which comprises breaking up a fibrous material into a state of fine subdivision, adding about /2 part of a flux oil to about 1 part of the divided fibrous material, adding caustic soda to the fibrous material and flux oil, digesting at 100 lbs. per square inch steam pressure for two hours the fibrous material, flux oil and caustic soda to form a fibrous pulp. dispersing in the fibrous pulp an asphalt and flux oil, picking up the mixture of the fibrous material, flux oil and asphalt in lay-v ers on a continuous blanket to form sheets, and submitting the said sheets of fibrous material, flux oil and asphalt to pressure and heat to remove water.

3. A method of preparing a building composition which comprises breaking up a fibrous ma? terial into a state of fine subdivision, adding about t part of a fiux oil to about 1 part of the divided fibrous material, adding a solution of lime to the fibrous material, digesting at 100 lbs. per square inch steam pressure for two hours the fibrous material, flux oil and solution of lime to form a fibrous pulp, dispersing in the fibrous pulp an asphalt and flux oil, picking up the mixtureof fibrous pulp, asphalt, flux oil and lime in layers on a continuous blanket to form sheets, and submitting the'said sheets to pressure and heat to remove water.

4. A method of which comprises preparing a composition board mechanically subdividing a fibrous material, adding a flux oil to the finely divided fibrous material, allowing the mixture of finely divided fibrous material and flux oil to stand for at least seven days, adding a lime solution oi. about concentration to the mixture of fibrous material and flux oil, digesting the mixture for about two hours at 100 pounds per square inch steam pressure, dispersing asphalt and flux oil in the mixture, picking up the mixture of fibrous material, flux oil, asphalt and lime in layers on a continuous blanket to form sheets, and submitting the said sheets to pressure and heat to obtain a composition board.

5. A method of preparing a composition board according to claim 4 in which asphalt is dispersed as a clay asphalt slurry containing copper naphthenate.

6. A method of preparing a composition board according to claim 4 in which the asphalt is displaced as a clay-water-asphalt slurry.

7. A method of preparing a composition board according to claim 4 in which asphalt is dispersed as a clay-asphalt slurry containing a metal salt of naphthenic acid.

8. A method of preparing a composition of fibre board which comprises breaking up a fibrous material .into a state of fine subdivision, im-

the finely divided material with about 95 part of a flux oil, allowing the mixture to stand for at least seven days, adding lime to the mixture, digesting at 100 lbs. per square inch steam pressure for two hours the mixture to form a fibrous pulp, dispersing asphalt with the fibrous pulp, picking up the mixture of fibrous'pulp, flux oil, asphaltand lime in layers on a'continuous blanket to form sheets, and submitting' the said sheets to pressure and heat to tion. which comprises breaking up a fibrous material into a state of fine subdivision, impregnating about 1' part of the finely divided fibrous material with about part of a fiux oil, allowing the mixture of fibrous material and flux oil to stand for at least several days, adding an alkaline solution to the mixture of finely divided fibrous material and flux oil, digesting at 'lbs'. per square inch steam pressure for two hours the mixture of finely divided fibrous material, alkaline solution and flux oil, dispersing asphalt and a metal salt of naph thenic acid in the fibrous material mixture, picking up the mixture of fibrous material, flux oil and asphalt in layers on a continuous blanket to form sheets, and submitting the sheets. to pressure and heat to form a building composition containing 1 part by weight of asphalt to 1 part by weight of the fibrous material.

11. A method of preparing a building composition according to claim 10 in which the metal salt of naphthenic acid is aluminum naphthenate. 12. A method of preparing a building composition according to claim 10 in which the metal salt of naphthenic acid is copper naphthenate.

- 13. A method of preparing a building composition according to claim 10 in which 1 part of the fibrous material, 1 part of the asphalt and 1 part of a mineral filler are used.

' CHARLES M. BASKIN.

NORMAN W. MCLEOD.

REFERENCES CITED The following references are of record in .the'

Oct. 1, 1940 

